Three passengers suing Carnival cruise lines for damages after an engine fire left their ship adrift for days are asking the company to pay US$5000 (NZ$5891) per year for life while the rest are seeking US$2500 (NZ$2946) to US$5000 for four to five years.

A lawsuit brought by 33 passengers of the ill-fated 2013 voyage could change how cruise lines insulate themselves from legal actions, according to maritime legal experts.

A second pending lawsuit with three-times as many plaintiffs has the potential to further undo the advantageous legal position cruise lines have long enjoyed.

Both cases stem from a February 2013 incident when the Carnival Triumph broke down after launching from Galveston, Texas for what was to be a four-day cruise with a stop in Cozumel, Mexico.

A fire broke out in the ship's engine room as it was returning from Cozumel. The Triumph was left without engine power, or air conditioning and working toilets.

Stalled in the Gulf of Mexico for five days, passengers described human waste seeping into hallways, and being forced to sleep on deck under makeshift tarps with no cooked food.

A federal judge in South Florida last week finished hearing three weeks of testimony from passengers and is expected to issue a judgment in the next two months.

The Miami lawsuit is the first from the Triumph incident to go to trial, with others in preparation, according maritime lawyers.

In a statement, Carnival Corp said that while it recognizes its guests experienced uncomfortable conditions, everyone returned safely and were provided with a full refund, a free future cruise and an additional US$500 ($589) per person.

"This is an opportunistic lawsuit brought by plaintiff's counsel and plaintiffs who seek to make a money grab," a company spokeswoman said.

One of the plaintiffs, Debra Oubre, 59, said she has experienced panic and anxiety attacks since the cruise, and also blames the experience for a urinary tract infection.

"It was chaotic. People were in dire need of help," said Oubre. "We were standing in line for food for two hours."

Federal judge Donald Graham has already ruled that the engine catching on fire is proof alone of negligence on the part of Carnival, a significant blow for the cruise line, according to Robert Peltz, a Miami maritime lawyer.

"It would seem rather obvious that ships shouldn't just catch fire and then have fire suppression systems that don't work," Peltz said.

Carnival has since started a fleet-wide "enhancement," including a major re-wiring of its engine rooms and improvements to fire safety and emergency power features.

Cruise lines like Carnival have successfully inoculated themselves against passenger lawsuits by printing stringent terms on their tickets that require passengers to waive their right to a class-action lawsuit.

Graham's ruling, which is expected to come in the next two months, could find the terms of conditions printed on the tickets, so-called "contracts of adhesion," to be overreaching.

The contracts have rankled some federal judges in southern Florida where several cruise lines are based, according to maritime lawyer, David Neblett. The splintering of myriad cruise cases for relatively meagre sums clogs their calendars, he said.

One term of the ticket contract is that passengers can only bring their cases to the Southern District of Florida and plaintiffs lawyers complain that people coming from other states to litigate is too costly for them.